I've been coding my experiment on a PC, but will run it on subjects in a MAC.

There's one issue that has been troubling me, and I'm wondering if there is a quick fix.

In my experiment, there is a training phase where subjects are presented with a stimulus, and when they respond, more events are added to the screen to provide feedback.

So basically there a picture on the screen with the possible correct answers under it. Then on the bottom of the screen are instructions of what keys to push to respond. Then, after they respond, new events are added to provide feedback, which essentially put brackets around the correct answer. At this point, I add instructions to push any key to continue, which presents the next trial.

Here's the issue:
Before they respond on the bottom of the screen is the instructions indicating what keys to push. After they respond, a new event is added over the instructions telling them to push any key to continue.

In the PC version, the text event must have a white background, because the new event "push any key to continue" covers up the "use XXXX keys to respond". However, when I run it on the Mac, the text event must have a clear background, because both events are now visible overlaying each other making it impossible to read what is being said. Any suggestions?

Hence the notification that things may be different on the new platform.

The way SuperLab behaves on the Mac is closer to how I would like it to behave than the PC, actually. On Windows, we've had issues with getting transparency to work correctly, but we haven't had this problem on the Mac. As a result, transparency is generally honored on the Mac, and ignored on Windows.

There is an additional issue that you've run into, but you may or may not have noticed. There isn't a system set up to automagically translate Windows fonts to Mac fonts, so you have to specify the fonts on each platform (both are stored, but independently).

Because of the various things you are trying to do, my recommendation is to put the text you would like displayed into a gif and display it as a picture event. Then, it will definitely look the same on both platforms--including covering up the existing text.